Re: [libvirt] [Qemu-devel] [PATCH 2/3] scsi-disk: Add device_id property

Kevin Wolf <kwolf(a)redhat.com&gt; writes: > Am 28.01.2019 um 17:55 hat Markus Armbruster geschrieben: >> Kevin Wolf <kwolf(a)redhat.com&gt; writes: >> >> > Am 28.01.2019 um 09:50 hat Peter Krempa geschrieben: >> [...] >> >> 2) Is actually using 'scsi-cd'/'scsi-hd' the better option than >> >> 'scsi-disk'? >> > >> > Yes, scsi-disk is a legacy device. Maybe we should formally deprecate >> > it. >> >> There's an internal use in scsi_bus_legacy_add_drive(), which in turn >> powers two legacy features: >> >> 1. -drive if=scsi >> >> Creates scsi-disk frontends. >> >> Only works with onboard HBAs since commit 14545097267, v2.12.0. >> >> 2. -device usb-storage >> >> Bad magic: usb-storage pretends to be a block device, but it's really >> a SCSI bus that can serve only a single device, which it creates >> automatically. >> >> If we deprecate scsi-disk, we should deprecate these, too. Can't say >> whether that's practical right now. > > Most likely not worth the effort anyway. I don't think it's blocking > anything. We could also wean them off the legacy device models.

>> >> 3) Since upstream libvirt supports qemu-1.5 and newer and 'scsi-cd' is >> >> already supported there, can we assume that all newer versions support >> >> it? (Basically the question is whether it can be compiled out by >> >> upstream means). >> > >> > I think so. >> >> Compiling out scsi-hd or scsi-cd, but not scsi-disk would be silly. All >> three devices are in scsi-disk.c. You'd have to hack that up to be >> silly. > > I understood this as a question about libvirt, i.e. whether libvirt can > drop/compile out their scsi-disk code and instead assume that scsi-hd/cd > are always present. Maybe I misunderstood, though? If questions remain, I trust Peter will ask.